The applicant is aware that packages with various trade names, which are made of a material that is composed of a sheet of aluminum covered on both sides, by a film of plastic, usually low-density polyethylene, and an outer layer of paper, are currently being distributed in the marketplace. An exemplary package is sold under the trademark TETRA BRIK of Tetra Laval Holdings & Finance S.A., Pully, Switzerland. Such packages are generally known in the industry and are identified hereinafter as "tetrabrick" type packages.
These materials, which are designed to have great stability in order to prevent contamination of the foods that they will contain, usually liquids, are therefore, undesirably stable when they are converted to urban wastes.
While recovery of the external paper layer is relatively easy, the separation of the plastic and the metal presents serious obstacles, and this makes it difficult to profitably recover these materials or their derivative products.
The applicant is aware of the existence at the present time of Patent of Invention DE 4,305,964 relative to RECYCLING OF COMPONENT MATERIALS, wherein different temperature zones are used in order to provide different gas compositions as fractions, with further processing of the coke residue.
Patent of Invention DE 4,304,294 pertains to an invention intended for the RECOVERY OF USABLE MATERIAL ORIGINATING FROM ALUMINUM-POLYOLEFIN, which is achieved by the removal of cellulose and carbonization of the aluminum below its melting temperature, using the carbonization gas as the heat source.
Patent of Invention number DE 4,410,145 pertains to an invention relative to the CONTINUOUS SEPARATION OF METALIZED PAPER FROM PLASTIC SHEET, by heat treatment and pelletization which provides a clean recovery process, for example, for aluminum and polyethylene.
Patent of Invention EP-484,507 pertains to a PROCESS FOR THE RECOVERY OF ALUMINUM AND POLYETHYLENE FROM METALIZED PACKAGING PAPERS, which includes separation of the printer's ink from the component materials in a separation column.
Patent of Invention EP-538,730 pertains to the RECOVERY OF POLYOLEFIN FROM MULTILAYER FILM, wherein the films or thin layers are cut into small pieces and are subjected to vigorous agitation in a solvent bath, in order to decrease the adhesive joint between the layers.
Patent of Invention EP-448,178 pertains to PROCESSING OF WASTES CONTAINING METALS AND COMBUSTIBLE MATERIALS, which deals with the combustion and cracking of exhaust gases, subsequent washing with acid and alkali and precipitation of the metallic compounds from the washing solution.
Patent of Invention JP 5-345,894 pertains to CHEMICAL RECYCLING OF PLASTIC, which permits high speed decomposition, at low temperature, etc., and includes the thermal decomposition of plastic wastes containing olefin-type and similar plastics in the molten state, and provides a high quality oil or gas in an economic manner.
Patent of Invention EP-629,818 pertains to a METHOD FOR THERMAL CLEANING OF OBJECTS, for example plastic, wherein said objects are heated in an enclosed space until pyrolysis begins, after which the temperature is strictly regulated, using a sensor and reducing or cutting off the supply of air or oxygen.
Patent of Invention EP-501,893 pertains to the REMOVAL OF THE THERMOPLASTIC COATING FROM SUBSTRATES, particularly polyethylene, from aluminum metalized paper, by applying a hot, mobile jet of an inert gas, to melt the coating and to push the molten material to one side.
Patent of Invention KR 89-04,486 pertains to the SEPARATION AND RECOVERY OF POLYETHYLENE AND ALUMINUM FROM RESIN WASTE, which involves the melting of polyethylene, by heating the device, and recovering the aluminum through the space between the ring and the wall of the mobile cylinder.
These patents of invention were located in the WPIL data base, while documents that refer to the dissolution of the polymer were not included in the search.
Within the context of the search previously conducted, the Applicant searched in Chemical Abstracts, and thus became aware of the following documents relative to the decomposition of polyethylene in an inert atmosphere. Namely:
T. Morimoto--J. Appl. Sci. 20, published the existence of a "Composition of the gaseous products of polymer combustion", through which it is known that the presence of methane, ethylene, acetylene and benzene has been detected in the thermal decompositions of commercial polypropylene in a nitrogen stream at 700.degree. C.
J. Michal, in Fire and Matls, 1, describes the "Toxicity of the thermal degradation products of polyethylene and polypropylene" in which decomposition at 400.degree. C. in a helium atmosphere was investigated, finding up to 48 different compounds, among which the most important are alkanes and 1-alkenes with 3 to 18 carbon atoms and small amounts of aromatic substances, such as benzene, toluene and ethylbenzene.
A. Hoff published an article on the "Degradation products of plastics", in which he stated that he had found that the compounds formed depend to a great extent on the raw material used. Twenty-five products were determined at 360.degree. C. in a helium atmosphere, in which hydrocarbons with 4 carbon atoms predominated.
In the publication by T. Morikawa relative to the "Evolution of soot and aromatic hydrocarbons of cyclic fold proceeding from the combustion and pyrolysis of polymers and low molecular weight hydrocarbons", the evolution of the production of polycyclic aromatic hydrocarbons had been studied, according to which, up to 1 g/g of benzo(a)pyrene is found as the decomposition temperature increases between 900 and 1000.degree. C.
From the same source of information and relative to the treatment of formed plastic products, the publication by M. Yoshida relative to the "Treatment of waste rubber and plastics", the plastic is mixed with a white inorganic filler, such as talc, melts and decomposes at a temperature that varies between 400 and 450.degree. C., and is distilled at a temperature that varies between 300 and 350.degree. C., to obtain three colorless fractions, specifically 10% light, 60% medium and 30% heavy.
A publication by T. Takahatake pertains to the "Treatment of synthetic polymer wastes" in which the polymer is mixed with powdered CaCO.sub.3 and subjected to dry distillation at a temperature that varies between 250 and 750.degree. C., and the fixed part mixed with the CaCO.sub.3 is calcined at a temperature that varies between 1000 and 1200.degree. C., and the CaO is mixed with water to purify the gases.
In the study by R. Kawabata relative to the "Formation of oils from thermoplastic resins", an oil is prepared by polyethylene pyrolysis at 420.degree. C. for 60 minutes, in the presence of a clay containing "alofan", and the presence of approximately 5% clay increases the production of oil from 12.8% to 84.4%.
The study by H. Ito et al. pertains to a "Treatment for polymer wastes or residues", wherein the polyethylene is first treated with a solvent to eliminate the solid by filtration, and after the solvent has been separated and recycled, pyrolysis is carried out to produce gaseous hydrocarbons and oil, which are recycled to the pyrolysis.
The study by S. Komiya pertains to the "Production of gases and oils from waste plastics", wherein the polyethylene passes from a hopper to a rotary cylinder, the surface of which is at a temperature that varies between 200 and 600.degree. C., to obtain a gas and an oil.
The study by K. Nagaya pertains to the use of "Pyrolysis of plastic trim for the production of combustible gases", wherein pyrolysis takes place at over 500.degree. C., and part of the residue .vertline.is used.vertline. in a high-temperature zone, wherein the temperature reaches 700 to 1200.degree. C., which is reached by burning another part of the residue with oxygen or air in the presence of steam. At 945.degree. C., the gas contains H.sub.2 O, CH.sub.4, C.sub.2 H.sub.6, and 32 percent other saturated hydrocarbons, 12% C.sub.3 H.sub.6 and 12% other unsaturated hydrocarbons, 10% CO.sub.2, 14% CO, and 2% other gases.
The study conducted by H. Nishizaki pertains to a "Treatment of polyolefin residues" wherein the polyolefins are decomposed by contact in a fluidized medium at a temperature that varies between 650 and 850.degree. C. to recover the olefins.
The publication by Y. Nozaki pertains to a study relative to "Pyrolysis oils obtained from thermal cracking of thermoplastic polymeric materials", wherein some formulas are presented to implement the cracking of the oils obtained by pyrolysis of plastics, in order to obtain, by heating at 310.degree. C. for a period that varies between 4 and 5 hours, an oil that has a flash point of 45 degrees.
S. Hattori refers to the "Thermal decomposition of waste plastics", wherein the plastic is heated in the presence of a metal or a metallic compound (NiO) at 800.degree. C., giving rise to a gas that contains 71 parts of H, 100 parts of CH.sub.4, 19 parts of C.sub.2 H.sub.4, 258 parts of CO and 9 parts of CO.sub.2.
In regard to acyclic compounds, the following documents were obtained from the same source as the aforementioned. Namely:
Patent of Invention GB 1,369,964, pertaining to the CONTINUOUS THERMAL DECOMPOSITION OF SYNTHETIC MACROMOLECULAR MATERIALS, which describes a device for the recovery of volatile products from the thermal degradation of polymers, by passing them through a tubular screw extruder, which has orifices for discharging the volatile products to a condenser, the tube being heated to 500.degree. C. to obtain 96.7 wt. % of a liquid product that contains 74.5% by weight of styrene, combined with PhMe dimers and trimers, C.sub.6 H.sub.6 and .alpha.-methylstyrene.
Patent of Invention JP 50-092,373 relative to the THERMAL DECOMPOSITION OF WASTE THERMOPLASTIC RESINS, wherein the thermoplastic resin decomposes on an aluminum bronze alloy surface, &lt;12% Al, and more than 10% of metals from groups II-VIII of the 4 th period, in the presence of steam, while the metallic roller is maintained at 450.degree. C.
Patent of Invention JP 50-115,282 pertains to the PRODUCTION OF FUEL BY THERMAL DECOMPOSITION OF PLASTIC, wherein the plastic is mixed with a lubricating oil to obtain fuels, specifically 227 grams of crushed polyethylene and 308 grams of oils, which are mixed and heated to 410.degree. C. to obtain 500 grams of fuel oil.
Patent of Invention JP 50-097,674 pertains to the GASIFICATION OF WASTE POLYETHYLENIC MATERIALS BY MEANS OF PYROLYSIS WITH ALLOYS, wherein the polyethylene is placed on a sheet of nickel steel, heated to 450.degree. C., with a thermal contribution of 0.03-0.29 cal/sec-cm-deg, which gasifies the polyethylene within 2 minutes, using a sample of 3 grams.
Patent of Invention JP 50-032,108 pertains to the existence of a DEVICE FOR THE PYROLYSIS OF HIGH-GRADE SYNTHETIC POLYMERS, wherein pyrolysis takes place in a double screw conveyor, in which the separation between the coil and the wall provides a space that is certain to prevent the adherence of the pyrolyzate to the wall, and pyrolysis is carried out at a temperature of 560.degree. C. to obtain 8% gas, 67% oil, and 25% wax.
Patent of Invention JP 58-172,322 pertains to the RECOVERY OF ALKYLBENZENE RESIDUES FROM POLYOLEFIN AND BENZENE PLASTICS by decomposing the polyethylene in an autoclave heated to 430.degree. C. with a solid acid catalyst, such as silica-alumina, at a pressure of 70 kg/cm.sup.2, and after cooling, a liquid product is obtained that contains 20% iso-PrC.sub.6 H.sub.5, 13% sec- and iso-butylbenzene, 12% EtC.sub.6 H.sub.5, 10% toluene and 5% PrC.sub.4 H.sub.5.
Patent of Invention DE 2,623,331 pertains to the LOW-TEMPERATURE PYROLYSIS OF POLYOLEFINS TO PRODUCE GASEOUS AND LIQUID HYDROCARBONS, wherein pyrolysis takes place at low temperature, that is, at 200.degree. C., i.e., the polypropylene is mixed with 9% AlCl.sub.3, to obtain approximately 19% gaseous hydrocarbons and 77% hydrocarbons with a boiling point that varies between 20 and 185.degree. C.
Patent of Invention HU 37,587, pertaining to HYDROCARBONS CONTAINING ALPHA OLEFINS FOR INTERMEDIATE INDUSTRIAL PRODUCTS FROM WASTE MATERIALS, in which an agitated reactor is used, and heated to 415.degree. C., to produce 3% of a gas and 97% of a liquid that contains approximately 2% coke.
Patent of Invention CS 219,595 relative to LINEAR ALKANES AND ALKENES, pertains to catalyzing the decomposition with TiO.sub.2, to produce linear alkanes and alkenes.
Patent of Invention JP 4-356,433 pertains to the PREPARATION OF METHANOL FROM ORGANIC RESIDUES, to obtain methanol by thermal decomposition of the plastic at a temperature that varies between 400 and 1200.degree. C., by introducing a gas containing oxygen and steam at a pressure of 10 atm., subsequently washing the gas at the discharge, and passing it through a column containing CaO--ZnO--Al.sub.2 O.sub.3 at 230.degree. C. and 40 atm.
Patent of Invention U.S. Pat. No. 5,326,919 pertains to the RECOVERY OF MONOMERS BY MEANS OF THE PYROLYSIS OF POLYMERIC MATERIALS, to obtain monomers with a low content of coal tars and coke by heating the polymer at 500.degree. C./second by contact with incandescent sand.
From the same source as the aforementioned inventions, but relative to heterocyclic compounds, a Patent of Invention WO 92-22,528 has been found relative to a PROCESS FOR CONTROLLED CATALYTIC AND SEQUENTIAL PYROLYSIS AND HYDROLYSIS OF MIXED POLYMER RESIDUES, wherein rapid pyrolysis takes place, which is catalyzed by acids or bases to convert the plastic to monomers and other valuable products in a sequential path without the necessity of cutting up the plastic beforehand, with pyrolysis taking place at a notably high temperature.
From the same source of information, but relative to macromolecular compounds obtained by reactions that involve only unsaturated carbon-carbon bonds, the following documents have been found. Namely:
Patent of Invention GB 2,136,437 pertains to a PROCESS AND EQUIPMENT FOR MANUFACTURING SIMILAR SUBSTANCES OR PARAFFINIC WAXES, wherein the material is burned to initiate pyrolysis, and the melted product decomposes to form a substance analogous to a paraffinic wax, which can be used as a fuel, for melted wax casting, in polishing, etc., and the combustible gas from pyrolysis is burned to produce the heat necessary for the process, while the device used to prepare the wax product is configured from a combustion basket with the upper part and the bottom open, and a small perforated basket located above the receptacle that receives the molten material.
Patent of Invention RO 71,349 pertains to the RECOVERY OF STYRENE FROM POLYMER RESIDUES, wherein approximately 70% of the styrene is recovered by means of thermal decomposition at a temperature that varies between 200 and 500.degree. C. in the presence of an asbestos catalyst with a CuO support.
Patent of Invention JP 53-055,384 pertains to TREATMENT OF PYROLYSIS PRODUCTS FROM POLYMERIC RESIDUES, which includes a vapor phase in which the polyethylene is combined with the wax residue that is produced by pyrolysis to obtain a liquid product.
Patent of Invention EP 502,618 pertains to the THERMAL DEGRADATION OF POLYMERS IN FLUIDIZED BEDS, in the preparation of low molecular weight hydrocarbons, such as light olefins, paraffins, naphthalenes, olefinic oligomers and waxes, by thermal degradation in a fluidized bed at a temperature that varies between 300 and 690.degree. C.
Patent of Invention GB 1,450,285 pertains to a PROCESS FOR THE PRODUCTION OF WAX, wherein waxes that can be used for polishing are produced by polyethylene pyrolysis below 350.degree. C., to obtain seven parts of soft grease products, with a pungent odor that melt between 70 and 82.degree. C., and 111 parts of a colorless, odorless wax residue that melts at a temperature between 90 and 100.degree. C.
Patent of Invention JP 5-214,022 pertains to a PROCESS FOR THE THERMAL DECOMPOSITION OF POLYOLEFIN RESIDUES, wherein the polyolefins decompose at a temperature that varies between 250 and 500.degree. C. to obtain waxes, oils, gases, etc., in a reactor that contains a catalyst placed on a screen.
Also from the same source as the previous groups, but relative to post-treatment production processes, the following information has been obtained. Namely:
Patent of Invention DE 3,037,029 pertaining to MODIFIED TARS AND AROMATIC PRODUCTS WITH A LOW BOILING POINT AND OLEFINS AND THE USE OF THESE TARS, wherein the polyethylene is mixed with aromatic hydrocarbons with a boiling point below 300.degree. C., such as anthracene oil or carbonaceous coal tar, in an inert atmosphere to prepare olefins with a low boiling point, as well as modified tars that are used to prepare coke, and a mixture of equal parts of coal tar and polyethylene heated to 370.degree. C. for 5 hours in an inert atmosphere, resulting in the production of 29% volatile products, including 1% benzene, 26% toluene, 53% ethylbenzene, 18% cumene and 2% other hydrocarbons.
The residue of 69% is subjected to a softening temperature of 118.degree. C. to obtain 8.6% insoluble quinoline and 37.6% insoluble toluene, and these three products are used to prepare electrodes.
Patent of Invention DD 285,506 relative to the COMPLETE RECOVERY OF POLYMERIC RESIDUES pertains to a process that requires no laborious separation or purification, wherein the plastic is mixed with superheated steam and treated with H plasma at a temperature of 100.degree. C. and 10.05-0.5 MPa during 1 ms to 30 seconds of rapid cooling.
A solid (coke or carbon black) and a gas formed by a mixture of C.sub.2 H.sub.2, C.sub.2 H.sub.4 and H are separated from the pyrolyzed stream, and this is washed to separate C.sub.2 H.sub.2, which is recycled to prepare the polymer.
Patent of Invention JP 53-045,384 relates to PYROLYZATION DEVICES FOR THERMOPLASTIC RESIN RESIDUES, wherein the plastic is decomposed in a pyrolysis tank at 400.degree. C. and the components produced dissolve in a tank at 300.degree. C. from which a distilled fraction is obtained.
Patent of Invention JP 52-049,506 relative to PLASTIC PYROLYSIS pertains to the pyrolyzation of plastic to produce an oil and a gas, recycling the oil with the plastic, and using it as a heating and transfer medium.
Patent of Invention JP 5-186,632, relative to the PRODUCTION OF LIGHT OILS BY MEANS OF HYDROLIQUEFACTION OF WASTE PLASTICS pertains to pulverizing the plastic and mixing it with recycled containers to pyrolyze the mixture in a catalytic reactor at a temperature that varies between 250 and 500.degree. C., and between 10 and 300 atm., using FeS.sub.2 as the catalyst, and the liquid effluent is placed in contact with a hydrogenation catalyst (Ni-Mo or Co-Mo) and is distilled to recover light oils.
Patent of Invention RO 102,366 pertains to PYROLYSIS OF MIXTURES OF POLYMERIC RESIDUES, wherein a mixture of tires and polyethylene is pyrolyzed at a temperature that varies between 450 and 600.degree. C., to prevent the formation of coal tars, sulfurated compounds, etc.
The following documents relative to the destructive distillation of carbonaceous materials were obtained from the same source as the previous groups. Namely:
Patent of Invention DE 2,424,605 relative to the PYROLYTIC TREATMENT OF ORGANIC RESIDUES, describes decomposition by heating to a temperature that varies between 750 and 900.degree. C. in the presence of an inert gas of a polyethylene mixture (among others), and a catalyst formed by oxides of heavy metals, such as Ba, Cr, Cu, Pb, Zn, Bi, or Ni, or compounds of Ba, Cr, or Cu, or mixtures thereof (0.05 to 5%), and a peroxide (ketoperoxide, ester peroxide or hydrogen peroxide) (0.15 to 15%).
Patent of Invention RO 78,462 pertains to a CATALYTIC PROCESS IN A DEVICE FOR THE THERMAL DECOMPOSITION OF POLYMERIC RESIDUES, which is implemented by decomposition in a tubular reactor, in which the material is entrained by an endless screw, and passes through three zones heated to temperatures that vary between 20 and 250.degree. C., between 250 and 450.degree. C., and over 450.degree. C.
The pyrolysis product is passed through a cracking catalyst, consisting of approximately 86% SiO2, 13% Al.sub.2 O.sub.3, 0.12% Fe.sub.2 O3, and 0.32% Na.sub.2 O.
Patent of Invention JP 6-080,970 pertains to a TREATMENT OF MACROMOLECULAR MATERIALS, indicating that hydrocarbons and a residue of heavy oils can be obtained by subjecting the plastic to a heat treatment.
Patent of Invention WO 92-04,423 pertains to the RECOVERY OF MONOMERS FROM THE PYROLYSIS OF POLYMERIC RESIDUES, indicating that by heating to over 650.degree. C., specifically between 650 and 1000.degree. C., in a fluidized bed reactor with steam as the carrier element, a gas is formed by 16.4% H, 0.8% CO.sub.2, 38.2% ethylene, 3% ethane, 1.2% acetylene, 9% propylene, 3.6% butylene, 27.2% CH.sub.4 and 0.6% CO by volume.
Patent of Invention U.S. Pat. No. 3,984,288 pertains to a TREATMENT OF RUBBER AND PLASTIC RESIDUES, describing a reactor with an endless screw extruder, wherein the product is melted at 350.degree. C., and passed to a decomposition zone heated to a temperature that varies between 500 and 800.degree. C., and from there to a distillation zone that varies between 300 and 400.degree. C., to obtain three fractions of products.
Patent of Invention DE 3,247,388 pertains to a PROCESS AND DEVICE FOR OBTAINING USEFUL RAW MATERIALS FROM PLASTICS RESIDUES, wherein the pyrolysis is implemented in a coking oven at a temperature that varies between 900 and 1200.degree. C., with the pyrolysis products being formed by 57 to 59% gases, 37 to 41% liquids, and 2 to 4% solids, including gaseous products H, CH.sub.4, C.sub.2 H.sub.4, C.sub.2 H.sub.6, C.sub.3 H.sub.6, C.sub.6 H.sub.6, PhMe and naphthalene.
Also from the same information source but relative to cracking of hydrocarbon oils, the following documents were found. Namely:
Patent of Invention JP 3-086,791, relative to the PRODUCTION OF LOW BOILING POINT HYDROCARBON OILS, wherein the polyolefins are mixed in a tank and the melted product is pyrolyzed, with the vapors being passed through a zeolite catalyst (HZSM 5), and a fraction of the product is recycled to the mixing tank.
Patent of Invention JP 54-043,278, relative to PARAFFINS AND OLEFINS FROM POLYOLEFIN RESIDUES, wherein the polyolefins decompose at a temperature that varies between 400 and 600.degree. C. in an explosion-proof boiler, air is removed and n-paraffins with from 11 to 20 C and olefins with a molecular weight between 180 and 250 are obtained.
The material reaches the boiler through a horizontal screw conveyor, and the gas formed in the refining zone, the upper part of the boiler, at a temperature that varies between 300 and 360.degree. C. is separated, condensed and recovered, with part of the condensate being returned to the refining zone to maintain the temperature.
Patent of Invention JP 56-045,984 relative to the PYROLYSIS OF POLYOLEFIN PLASTICS, wherein the polyethylene is decomposed at a temperature that varies between 430 and 470.degree. C., and the product is passed through a bed formed by glass beads with a diameter of 6.5 millimeters and a temperature of 250.degree. C. to obtain a hydrocarbon oil.
Patent of Invention JP 6-184,555 relative to THERMAL DECOMPOSITION OF WASTE PLASTICS, wherein the plastic and high temperature steam are introduced into a horizontal decomposition oven, the walls of which are heated from the outside, and the device has a shaft with rotors.
Patent of Invention JP 60-190,494, relative to the PRODUCTION OF SUBSTANCES ANALOGOUS TO PARAFFINIC WAX, wherein the polymer is melted in a perforated basket and drips through the holes in the bottom of the basket onto a bed of wire-form catalyst, where the polymer is pyrolyzed at high temperature, continuously, in an oxygen-poor atmosphere, and the fuel gas produced is returned to the basket where it is burned and the molten paraffin wax is collected in the bottom of the reactor, and is used as fuel or as a filler material.
Patent of Invention JP 60-049,086 relative to a PROCESS AND DEVICE FOR THE PYROLYSIS OF POLYETHYLENE RESIDUES, wherein the vessel in which pyrolysis takes place is heated exteriorly from the outside, at a controlled temperature to prevent overheating and the accumulation of C in the walls.
To this end, KNO.sub.3 and NaNO.sub.3 sand is used as the heating medium in the jacket that surrounds the vessel, and due to the combustion of gases or oil, the temperature of the medium is maintained and varies between 450 and 600.degree. C., and the temperature in the interior of the vessel is between 400 and 500.degree. C.
The vessel has an agitator, an exhaust for the gas produced, and a discharge valve in the bottom, and the gas produced passes to a second decomposition reactor and is recovered as oil in the condenser.
Patent of Invention JP 4-086,790, relative to the PRODUCTION OF LOW BOILING POINT HYDROCARBON OILS, wherein the polyethylene is melted in a tank, the molten product is pyrolyzed in another tank, and at least a portion of the liquid fraction is separated from the pyrolysis gas by liquefying it, and is recycled to the pyrolysis tank and the tanks are passed through a zeolite catalyst (HZSM 5) for its catalytic conversion.
Patent of Invention JP 53-045,302, relative to HYDROCARBON OILS OBTAINED FROM DEGRADED POLYETHYLENE RESIDUES, wherein the polyethylene is melted at 400.degree. C. in the absence of oxygen, and is thermally decomposed after heating, and a hydrocarbonated oil is obtained after fractionation.
Patent of Invention JP 4-180,995, relative to the PRODUCTION OF AROMATIC HYDROCARBON OILS BY PYROLYSIS OF POLYOLEFINIC PLASTIC RESIDUES, wherein aromatic hydrocarbons are obtained by pyrolyzing the olefinic plastics, and the vapors produced are passed through a zeolite catalyst bed (HZSM-5) at a temperature that varies between 350 and 550.degree. C., the effluent obtained is cooled to separate the volatile hydrocarbonated gases from the low boiling point hydrocarbonated oils, and finally the hydrocarbonated gases are heated and introduced into the catalytic bed, to obtain contact conversion.
Patent of Invention WO 94-20,590, relative to a PROCESS FOR RECYCLING WASTE PLASTICS, wherein the plastic is decomposed in a diluent, such as hot oil by means of actions that give rise to free radical precursors at low temperature, such as vinyl chloride or polyurethane and thermal decomposition takes place at 375.degree. C. and the diluent can be recycled to the process.
Patent of Invention JP 5-171,159, relative to a DEVICE FOR THE TREATMENT OF WASTE PLASTICS BY PYROLYSIS, wherein the plastic is subjected to dry distillation in an oven, and the gaseous effluent is condensed to yield a product similar to wax that melts between 40 and 100.degree. C., which can be used as a heat accumulating material, comprising the system for storing this material in a storage tank and the utilization of its accumulated energy by the dry distillation oven; the cost of constructing the device is low and energy consumption is reduced.
Patent of Invention EP 555,833, relative to a PROCESS AND A DEVICE FOR PRODUCING A LOW BOILING POINT HYDROCARBON OIL FROM PLASTIC RESIDUES OR RUBBER RESIDUES, wherein the plastic is thermally decomposed to produce a vapor that is placed in contact with an acid catalyst containing HCl as a decomposition activator for cracking the gaseous products, thus producing a hydrocarbonated oil with a low boiling point.
Patent of Invention JP 55-071,789, relative to PYROLYSIS OF POLYOLEFINIC PLASTICS RESIDUES, wherein the plastic is pyrolyzed to recover oligomers and hydrocarbonated oils.
The desired product is obtained by controlling the pyrolysis temperature between 350 and 470.degree. C., and that of the gaseous phase above the material to be pyrolyzed, which can vary between 110 and 470.degree. C., and when these temperatures are at 420 and 300.degree. C., respectively, after 5 hours, 91.2% of a hydrocarbon with a greasy appearance is recovered (average m.p. 287, with 73% hydrocarbons with 5 to 33 C).
Patent of Invention DE 4,114,434, relative to REDUCED PRESSURE PYROLYSIS OF SYNTHETIC ORGANIC WASTES, ESPECIALLY WASTE PLASTICS, WITH MINIMUM FORMATION OF COKE, wherein pyrolysis is carried out at a temperature that varies between 220 and 350.degree. C. and at a pressure between 10 mb and 1 bar to minimize the formation of coke, and pyrolysis can take place in the presence of additives (phenols, sulfurated compounds, alkane, amines and water), a radical initiator (ter-BuOOH) or hydrocarbonated oils.
Patent of Invention JP 6-128,569, relative to a PROCESS AND A DEVICE FOR THE FORMATION OF HYDROCARBONATED OILS WITH A LOW BOILING POINT, wherein oils are obtained starting from those with low boiling point, which are useful as a raw material for gasolines, by being passed through an extruder, a mixing tank of the molten product and a tank with a zeolite catalyst, and a portion of the molten material from the pyrolysis tank is recycled to the extruder.
Patent of Invention JP 6-228,568, relative to a PROCESS AND A DEVICE FOR OBTAINING HYDROCARBONATED OILS FROM PLASTIC RESIDUES OR FROM RUBBER RESIDUES, wherein a gas is obtained by pyrolysis, and a product with a low boiling point is obtained by cracking the gas, and the catalyst used for cracking is a transition metal with a particle size of less than 0.1 .mu.m.
Patent of Invention JP 5-279,671, relative to a TREATMENT OF WASTE PLASTIC BY MEANS OF PYROLYSIS, USING RADIATION, wherein for pyrolysis, the plastic is subjected to beta or gamma radiation at approximately 300.degree. C. in an inert atmosphere of H, steam or air, and depending on which gas is used, a specific ratio of gas to liquid is obtained in the product obtained.
Patent of Invention JP 6-279,762, relative to RECOVERY OF FUEL-OIL FROM THE TREATMENT OF INDUSTRIAL WASTES, CONTAINING POLYOLEFINS BY MEANS OF PYROLYSIS, wherein the polyolefin is treated with steam at a supercritical temperature in a pressure vessel, to obtain an oily substance of low-viscosity oils.
Patent of Invention JP 5-059,372, relative to the PRODUCTION OF FUEL-OIL FROM POLYOLEFINIC RESINS, wherein a fuel oil is obtained (gasoline with a high content of aromatic substances), by catalytic conversion of the products of pyrolysis at a temperature that varies between 300 and 550.degree. C., with the conversion taking place by passing the vapors through a bed of REY zeolite at a temperature that varies between 200 and 600.degree. C.
Patent of Invention CS 275,924, relative to the PRODUCTION OF LOW MOLECULAR WEIGHT ALKENES BY COPYROLYSIS OF PETROLEUM FRACTIONS, wherein pyrolysis is achieved with gasoline, kerosene or gas-oil with 3-30 wt. % of polyethylene in the presence of steam at a temperature that varies between 600 and 900.degree. C., as well as a charging steam ratio of 1 to 2, a residence time of 0.16 seconds, and a temperature of 820.degree. C., which yields a product that contains 1.0% H, 16. 1% methane, 4.2% ethane, 31.3% ethylene, 15.4% propylene, 4.7% 1,3-butadiene, and 27.3% of other products by weight.
Patent of Invention JP 53-034,232, relative to THERMAL DECOMPOSITION OF PLASTICS RESIDUES, wherein thermal decomposition takes place in the presence of Ni at a reduced pressure, so that 130 grams of heated polyethylene in a stainless-steel vessel in the presence of Ni at 500.degree. C. and 500 torr yields 120 grams of oil, 7.5 grams of gases and 2.6 grams of residue.
Patent of Invention JP 5-279,673, relative to a DEVICE FOR THE RECOVERY OF FUEL-OIL FROM THE TREATMENT OF WASTE FOAMED PLASTICS, wherein the plastic is melted with an organic solvent to improve fusion in a closed vessel, the mixture is pyrolyzed and the fraction is evaporated, by passing it through a catalytic reactor.
Patent of Invention JP 59-124,992, relative to the RECOVERY OF SPENT POLYMERS AS FUELS, wherein the polymer is fed into the bottom of a reactor vessel, containing a molten metal, at a temperature of least 250.degree. C., which produces pyrolysis of the plastic and the gaseous product that is prepared is cooled, and a gaseous fraction and a liquid fraction are separated, using molten lead at 500.degree. C., from 86 grams of polyethylene, to obtain 65 grams of a liquid fraction and 20.1 L of a gaseous fraction which is used as a fuel; it should be pointed out that this Patent of Invention was obtained from the same sources as the previous ones, and refers to the area of the production of gasogenic gas, water gas, or synthesis gas.
Finally, the applicant also obtained the following two patents of invention from the same sources as the previous patents, but they are related to fuels not provided for in other places. Namely:
Patent of Invention WO 93-09,207, relative to a PROCESS FOR THE TREATMENT AND DESTRUCTION OF DOMESTIC AND/OR INDUSTRIAL WASTES AND FUEL PRODUCED FROM SAID WASTES, wherein different residues are mixed with polyethylene, to obtain, after they are melted, a product with a heating power of 13.5-16.5 mg/kg.
Patent of Invention JP 56-122,894, relative to a FUEL FROM PLASTICS RESIDUES, wherein the plastic is pelletized with lime or limestone, and the mixture is pyrolyzed at 200.degree. C. (the CaO stabilizes the HCl when PVC is used) to produce a combustible gas.
In accordance with the information received, the applicant has no knowledge of the existence at the present time of a Patent of Invention relative to a method, device or process that permits the recovery of the outer layer of paper that covers "tetrabrick type" packages, thus permitting the separation of the plastic and the metal; this operation involves many problems, which make it impossible, or at least extremely difficult, to achieve a profitable recovery of the latter or of products derived therefrom.
In spite of the existence of an extensive bibliography in this regard, the processes described are based on direct heating, which is considered a disadvantage when a readily reactionable element such as aluminum is present, or indirect heating through a cylindrical housing, and the entrained product is moved through its interior by means of an endless screw.